FX.co ★ UK Core RPI Inflation Cools Sharply in September, Easing to 0.1% MoM

Core retail price inflation in the United Kingdom slowed markedly in September 2026, with the Core RPI rising just 0.1% month-over-month, down from a 0.6% increase in August. The latest figures, updated on 21 October 2026, highlight a clear deceleration in underlying price pressures compared with the previous month.

The data compare monthly changes in core retail prices, stripping out more volatile components to give a clearer view of underlying inflation trends. August’s 0.6% month-on-month gain, measured against July, has now been followed by a much more modest 0.1% rise in September relative to August. This sharp slowdown may be closely watched by markets and policymakers as they assess the momentum of inflation heading into the final quarter of the year.